In today’s HVAC market there are a huge number of piping systems, materials, and brands to choose from, all offering a range of advantages and disadvantages. This leaves designers, engineers, consultants, estimators, installers, and asset owners with the challenging question of ‘which option should I choose?’
Whilst there are systems which have been around for centuries there are more modern innovations which are coming to the fore across the HVAC industry globally. Some may say, “if it isn't broken why fix it” but there are many challenges facing the HVAC and construction industry from budget pressures to risk management to challenging project delivery timeframes to quality control and more. This gives the question ‘which option should I choose’ a much deeper and more complex meaning and calls for a more considered approach to answering this question. Which option has best long-term value? Which option helps deliver the project on time and on budget? Which system gives best long-term performance? A key theme emerges here, this decision cannot be solely made on short-term gains or wins alone but must consider the ‘long-term’, the entire life cycle of the facility in which it is being installed.
In this blog we will have a brief look at the pros and cons of 2 pipe materials commonly used in today’s HVAC industry; steel and copper and a more modern innovation to the HVAC sector; Europress 304 Stainless Steel. In writing this blog we are primarily thinking of chilled (CHW) and heating (HHW) water applications.
Steel Pipe & Fittings
Steel pipe and fittings have been around since the early 1800’s. Traditionally in the HVAC industry welding or thread and socket jointing methods are common and in more recent times the roll groove system is used. Let’s look at some of the advantages and disadvantages of steel pipe and fittings:
Advantages
- Durability and strength
Arguably one of the main benefits of steel pipe and fittings is their durability and strength. Steel has an excellent ability to withstand pressure and temperature fluctuations which can happen in an HVAC installation.
- Low material cost
Steel typically has a low material cost which can be attractive when solely considering material costs.
- Long service life
When used under appropriate circumstances and with suitable protection in place, such as corrosion prevention, steel pipework typically has a long service life.
- Versatility
Steel pipework is a versatile piping system suitable for a range of applications including heating and cooling water, steam, and refrigerants.
Disadvantages
- Higher installation costs
While steel pipe and fittings will likely have a lower material cost it is important to consider the installed cost, which is the true cost of a project. Welding or thread and socketing is comparatively labour-intensive resulting in higher installation costs. In saying this, roll groove systems can help to provide a quicker installation. The point here is to carefully consider the installed cost over just material costs.
- Weight
Steel is heavy compared to copper and Europress 304 stainless steel which will increase weight loading requirements and likely result in higher bracketing and seismic requirements adding cost to an installation. The weight factor will also make the pipework harder for installers to handle during the installation.
- Corrosion susceptibility
Although corrosion protection is used such as inhibitors, steel itself has a high susceptibility to corrosion when moisture and oxygen come in contact. It is also important to consider water quality as this can also significantly impact how steel will perform long-term.
Copper Tube & Fittings
Copper is widely regarded as a tried, tested, and proven piping system. Installers for generations have used copper with the more traditional brazed jointing method and in more recent years we have seen the rise of press-fit technologies which have added faster installation benefits. Let’s look at some of the advantages and disadvantages of copper tube and fittings:
Advantages
- Durability and longevity
Copper is well known and proven for its strength and resistance to corrosion in varying temperatures making it a good solution for mechanical services.
- Workability
Installers love working with copper as being a softer metal it is easy to work with, easy to cut, and easy to form. This can speed up the installation process and, in some cases, may save fittings as it can be easily formed.
- Fast installation
Linking to the workability advantage, particularly press-fit copper offers fast and easy installation which can again be a key contributor to generating project savings on the installed cost.
Disadvantages
- Wear and erosion
Given copper is a comparatively soft metal, particularly in hot water applications and in the presence of high velocity, copper is susceptible to internal erosion in both the tube and particularly at a change of direction which can lead to higher maintenance costs and a reduced life expectancy of the system meaning copper may have a higher life-cycle cost than other alternatives. In saying this, this issue can be overcome by paying particular attention to the system design and ensuring velocity is controlled. The graph below shows the rate of erosion in copper vs stainless steel as velocity increases.
- Cost fluctuations
Copper typically has a higher susceptibility to cost fluctuations which can make it unpredictable over the course of particularly a long-term project.
- Increased malleability
Copper has a higher malleability than other metals which can increase bracketing requirements which may contribute to increased project delivery costs.
- Water quality
Copper can react adversely to different types of water quality. Although treatment options are often used, this can often extend back to the original water supply. Bore water supplies can be more aggressive and in heated water applications can lead to deterioration in copper pipework. In contrast, surface water supplies don’t tend to be as aggressive and may be more suited to copper.
Europress 304 Stainless Steel
Stainless steel has long been recognised as a high-end solution for HVAC pipework and with this perceived to be significantly higher cost. However, solely from a price viewpoint, Europress 304 Stainless Steel is often found to be very competitive with copper. It will be more than steel however, but again when you consider the potential reduction in installation costs and the full life cycle of the installation, then Europress 304 Stainless Steel becomes a very attractive option for HVAC installations as it delivers a great balance between a cost-effective solution and long-term durability and functionality. Let’s look at some of the key advantages and disadvantages of Europress 304 Stainless Steel:
Advantages
- Fast installation
Contributing to up-front capital savings on a project, the speed and ease of installation of Europress 304 Stainless Steel can contribute project savings of up to 30% compared to traditional jointing methods.
- Size range
Europress 304 Stainless Steel is available in sizes from 15mm right up to 168.3mm (the equivalent size of a 150NB or 6” pipe). Particularly in the large sizes, Europress is considerably lighter than options such as steel which reduces weight loading, bracketing, and seismic requirements a further opportunity to achieve project savings through value engineering.
- No hot works
Europress 304 Stainless Steel uses battery powered pressing tooling eliminating the need for hot works onsite reducing fire risk and improving asset and people safety.
- High wear/erosion resistance
Europress 304 Stainless Steel has a high resistance to internal erosion in high velocity or heating water applications. Europress can handle velocities of over 2m/s with minimal impact. This may allow designers to reduce pipe sizing, achieving further capital savings without risking the integrity of the pipework.
- Cost stability
Europress stainless steel is less susceptible to cost fluctuations giving relative price consistency across the duration of a project or multiple projects.
- High corrosion resistance
Even in aggressive water supplies, Europress stainless steel has a higher corrosion resistance increasing the service life expectancy of the piping system and lowering maintenance costs, a life-cycle cost saving for the asset owner.
- High tensile strength
The high tensile strength of Europress 304 stainless steel gives increased rigidity and durability, enhancing the service life while also reducing bracketing requirements, a further capital saving.
- 100% recyclable
Europress 304 stainless steel is manufactured from a high proportion of recycled material and is 100% recyclable, making Europress an ideal solution for a sustainable future meeting green building requirements.
Disadvantages
- Workability
From an installers point of view, being a harder metal than copper stainless steel will be harder to cut and form. However, this can be overcome by using the correct stainless steel rated cutting tools and tube formers.
- Corrosion from chlorides
Stainless steel, even 316L stainless steel, is susceptible to corrosion from a high concentration of chlorides. Whilst this is unlikely in a mechanical services installation, it is important to ensure you select approved pipe insulation as some insulations contain chlorides which in heating water applications, particularly above 50°C, have been known to draw chlorides out of the insulation resulting in corrosion and pin-holing in stainless steel pipework. Simply, ensure you select chloride free insulation when installing stainless steel pipework.
In conclusion, while every project must be considered in its own right, to answer the question ‘which piping system should I choose’ it is important to consider the life-cycle value of each option. What innovations, technology, or value engineering can be applied to deliver the best outcome for the project. What option will have the best life-cycle return on investment. While steel and copper have delivered great outcomes in the past, new technology such as the Europress 304 Stainless Steel is fast becoming recognised as a piping system which delivers an excellent balance between cost-effectiveness and a long-term value for installers and asset owners alike.
To learn more about Europress 304 Stainless Steel visit our website or reach out to our team today to discuss how this system can benefit you and your upcoming HVAC projects.
304 Stainless Steel HVAC Systems